More Mini Implants, Better Denture Stability? A New Study Puts the Numbers to the Test
Why Implant Numbers Matter for Denture Comfort
For people who have lost all their lower teeth, loose dentures can be one of the biggest daily frustrations making eating, talking, and even smiling uncomfortable. Mini dental implants (MDIs) have become an increasingly popular solution because they are slimmer, require less invasive surgery, and cost less than conventional implants.
But a key question remains:
How many mini implants are actually needed to keep a lower denture stable and comfortable over time?
A new study explored this debate by comparing the performance of 2, 3, and 4 mini dental implants in supporting a lower overdenture. The researchers focused on two practical aspects:
Retention – how firmly the denture stays in place
Attachment wear – how much the small nylon components inside the denture degrade after repeated use
Their findings offer useful guidance for clinicians and patients planning denture treatment.
What the Researchers Did
The research team created nine jaw models mimicking an atrophic (severely shrunken) lower jaw one of the most challenging cases for denture retention.
They placed mini implants in three configurations:
2 implants (at canine positions)
3 implants (midline + canines)
4 implants (distributed between lateral incisor and premolar regions)
Each denture went through 1,080 insertion removal cycles, simulating one year of daily use (assuming three removals per day for cleaning).
At each interval, the team measured:
Dislodgment force using a digital force gauge
Microscopic wear on the nylon attachment inserts
What They Found
1. More implants = stronger retention
From the very first measurement, dentures supported by 4 mini implants showed the highest retention force. This advantage continued throughout the one-year simulation.
4 mini implants: significantly stronger retention than 2 or 3
2 vs 3 mini implants: no meaningful difference in retention
2. All attachments lost retention over time
Regardless of implant number, retention dropped significantly after one year of simulated use.
However, the rate of decline differed:
2-implant overdentures retained only ~10% of their initial strength
3-implant overdentures: similar decline
4-implant overdentures kept about 36% of their original retention
This suggests that more implants help slow the rate of wear and retention loss.
3. Wear on the nylon inserts was inevitable but least severe with 4 implants
Microscopic analysis showed abrasion and compression in all inserts.
But again, more implants showed a protective effect:
4-implant group: smallest increase in insert diameter (least wear)
2 & 3-implant groups: significantly more wear, with no difference between them
This means the load was better distributed when four implants supported the denture.
What It Means for Patients and Clinicians
The study provides clear, practical insights:
Four mini implants offer the best long-term retention and lowest attachment wear.
Two implants still provide acceptable retention, and since adding a third implant did not make a difference, a 2-implant overdenture may be the most economical and minimally invasive option for many patients.
Three implants may not justify the added cost or surgical risk, since performance was similar to using just two.
For patients with highly atrophic jaws or higher retention needs, four implants may be worth the investment.
Conclusion
While all mini implant configurations experienced retention loss after one simulated year, using four mini implants clearly resulted in stronger, longer-lasting denture stability and less attachment wear. However, because there was no difference between two and three implants, a 2-implant overdenture remains a safe, cost-effective option for many patients and may reduce surgical risks especially in challenging atrophic mandibles.
Original Article
“The Effect of Mini Dental Implant Number on Mandibular Overdenture Retention and Attachment Wear”
BioMed Research International, 2023.
DOI: 10.1155/2023/7099761